Info regarding use of IRQ

Question

Hi I’ve been successfully able to establish a connection between the W5500 and an AT32UC3. Worked nearly out of the box (after discovering a wiring error caused by myself). I was able to port the loopback example from the Wiki successfully and establish a connection. Now I was wondering what needs to be done to make use of the interrupt the W5500 provides (hoping that I can reduce the amount of traffic on SPI between the UC3 and the W5500 since I have some other devices as well). Yet, I was unable to find such information in the Wiki. I only implemented the read, write, select and deselect functions for my controller (which was easy). Are there callback functions for using IRQ as well, which do I need to implement and what are they supposed to do? I saw a function named enter/exit critical section. I guess these are supposed to disable/enable IRQs or similar. Are these mandatory?

somnatic · Answer

Hi midnightcow I understand that data must not be sent or received in the interrupt handler. I do not want/need to do this. In my program main loop, I have the tcp_loopback part which continuously performs SPI transfers. What I meant was not to require these transfers until really something has changed. Can this be achieved with the IRQ signal line? So can I say that if a transfer needs to be performed, the IRQ line will inform me, I will set a flag and then (some time shortly after in my main loop) I will initiate the SPI transfer? Or does the IRQ line only signal specific events and I will need to use polling in any case.

somnatic · Answer

Do you plan on adding this feature to the W5500 driver? fyi: I made a Altium library (schematic + footprint + 3D) for the W5500, after our internal review I can send it you if you want to have it (plus some screenshots how it looks so you can review it as well).

somnatic · Answer

Hi I attached the Altium library as promised. Use at own risk. 836×814 148 KB 677×639 43.9 KB w5500-altium.zip (65.2 KB)

somnatic · Answer

I could only attach 3 files, therefore added 3D view here 792×612 91.8 KB